L25D - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 27th October 2011, 11:48 PM   #1
diyAudio Member
 
sketchyphish's Avatar
 
Join Date: Jun 2010
Location: Ipswich, Suffolk
Send a message via Skype™ to sketchyphish
Talking L25D

I am looking to build my first amp with help from a friend in electronics. Ive been looking around and found that the L20D is very popular, but on more searching have decided to go for the L25D although ATM i dont know the differences between them. Anyone got any idea's or comments ??

Also i was finding it hard to work out what power supply to use....
At first i was thinking im gonna need to get a toroid of about 60-70v, but thats why im here.
From what i am aware the actual peak voltage from a rectified ac power supply is actually 1.414 times the amount. i.e 45vac would get me about 63.6vdc ? Correct me if im wrong as im sure i read somewhere that you then times the peak by about 0.63 to get the actual output.
YES THIS CONFUSES ME......so any help would be appriciated.
I need to work out as well whether i can use a single say 600va supply for 2xL25D. Again it was suggested to provide about 1.25 times the required maximum power.
If i get a toroid with 2x50vac secondaries and connect the correct two wires together will i end up with a three wire 50-0-50 ??
Once again guys thanks for any advice and please feel free to enlighten me on anything i am clearly missing.

Peace
  Reply With Quote
Old 28th October 2011, 08:23 AM   #2
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
If you don't mind reading a bit, this link will answer most of your questions.....

Elliott Sound Products - Linear Power Supply Design
  Reply With Quote
Old 28th October 2011, 09:35 PM   #3
diyAudio Member
 
Join Date: Jul 2004
Location: Mountain View, CA
Why linear?

I've been reading this forum like crazy lately and the consensus seems to be that you can't beat these SMPS for price and quality

Connexelectronic

Re L25D vs. L20D vs. L15D, these are in decreasing order of suitable voltage ranges.

I believe in Table 1, p.4 of the below link that AMP7S-150 corresponds to thge L15D and AMP7S-200 to the L20D.

http://www.inductor.com/irf/iraudamp7s.pdf

I get the impression that the designer of these modules favors the L15D for sound quality

http://www.diyaudio.com/forums/class...-irfi4019.html
__________________
-----------------------------------------
Noah
  Reply With Quote
Old 29th November 2012, 04:12 AM   #4
diyAudio Member
 
Join Date: Nov 2012
I have enjoyed looking over these posts to try and get some clues I am looking for. I am running 2 L25D boards with +- 70 volts. They are both ocp'ing far too early in my opinion. I looked at the board, and it looks like the ocp resistors are the same as for the amp7s. Checking the transistor on voltage shows it to be pretty much identical to that for the original single package with two transistors design. So it appears to have twice as much transistor, but it uses the same heat sink, and the resistors defining the overcurrent are the same. This tells me that the board isn't prepared for a 4 ohm load even though it has enough transistor to do it. Of course, I could be wrong, and there could be some other reason why my boards are tripping so early.
  Reply With Quote
Old 29th December 2012, 01:34 AM   #5
elukasz is offline elukasz  Australia
diyAudio Member
 
Join Date: Dec 2012
Quote:
I have enjoyed looking over these posts to try and get some clues I am looking for. I am running 2 L25D boards with +- 70 volts. They are both ocp'ing far too early in my opinion. I looked at the board, and it looks like the ocp resistors are the same as for the amp7s. Checking the transistor on voltage shows it to be pretty much identical to that for the original single package with two transistors design. So it appears to have twice as much transistor, but it uses the same heat sink, and the resistors defining the overcurrent are the same. This tells me that the board isn't prepared for a 4 ohm load even though it has enough transistor to do it. Of course, I could be wrong, and there could be some other reason why my boards are tripping so early.
Looking at the pdf document (table 1) supplied by noah katz - is L25D same as AMP7S-200? This amplifier works only with 8ohm speakers.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 07:27 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2